Change in Visible Noise after Changing Lens
Sharpening: I am using exactly the same procedure to process the RAW files as with the Canon lens.
JPG: I am not shooting JPG, just RAW, processed to 8-bit TIFF in dcraw 8.39.
Live View: the 20D has no Live View.
The idea that the lens electronics/motor(s) add noise is interesting and something I had never thought of.
Thanks to those who answered.